Fired heaters are common process units in chemical plants. The fired heaters heat process streams to reaction temperatures, and provide heat to process streams that have endothermic reactions. A fired heater has a general configuration of a tube for carrying a process fluid inside a shell wherein burners are used to combust a fuel to heat the tubes.
Fired heaters occupy significant space, and the fired heaters often heat the process fluids above desired temperatures. With more complex processes, and with upgrades to processes in chemical plants, new configurations are needed to reduce the area taken up by fired heaters, to control the outlet temperatures of process fluids, and to provide for new efficiencies in the heating of process fluids.